Basic implementation of partial scoring.

[meisterT]

This follows the legacy spec in:
https://icpc.io/problem-package-format/spec/legacy.html#graders

We might decided at a later point whether we want to support this or just the new (currently draft) spec, but basic constructs of the change should be the same.

Not yet implemented:

• any form of testing
• anything on the team interface
• shadowing

Part of #2518

[meisterT]

Some notes:

• there's a to-do already, but we need to talk about internal precision and precision in presentation
• we should add to the jury submission page some info that allows following the result calculation with test case groups (should be easy to do with the existing function)
• the number of tries on a scoring scoreboard should really be the number of total tries (not until the first correct attempt like for pass-fail)
• it seems we are not handling the accept_if_any_accepted case always correctly, needs more testing
• while we can ingest results from a primary CCS now, we don't compare the scores yet for shadow differences
• the layout of the shadow differences table needs to be fixed
• optimization problems are by their very nature less deterministic as they incentivize teams to do stuff like try this approach for that amount of time, then this other approach for that amount of time and generally the use of RNG is much more prevalent